The weird truth about calories and why food labels get them so wrong

WHEN you’re navigating the complicated world of vitamin, the calorie feels mercifully easy. An easy measure of the power in our meals, energy sit on the coronary heart of typical weight management recommendation. Eat too many, or fail to burn sufficient, and you’ll placed on weight. Need to slim down? Eat much less and transfer extra. Because the saying goes, “a calorie is a calorie is a calorie”. Dig just a little deeper, nevertheless, and you discover it isn’t that easy.

This concept of the physique as a furnace and meals as its gasoline was popularised by Wilbur Atwater within the nineteenth century. He deduced that there are three predominant elements, or macronutrients, with which we will calculate the calorie content material of any meals: protein and carbohydrates include 4 energy per gram, whereas fat include 9. Mix these and the outcome informs the calorie content material on meals labels in every single place.

However take into consideration how meals is consumed and also you hit your first downside. Take an orange, says Giles Yeo, a geneticist on the College of Cambridge and creator of Why Energy Don’t Rely. An orange is principally carbohydrate, or sugar. “Whenever you drink orange juice, your physique will take up the sugar [quickly] as a result of there isn’t any digestion required,” says Yeo. Eat orange segments, nevertheless, and it takes power for the digestive system to work on the fibre and extract the sugar. “Physiologically, your physique does utterly various things with it, with precisely the identical calorie hit,” says Yeo.

Orange juice causes a extra fast spike in blood sugar ranges than the orange segments, for instance, and common surges in blood sugar …